Base station and user equipment

ABSTRACT

The present disclosure pertains to a user equipment for a mobile telecommunications system includes circuitry including a receiver and a transmitter and which is configured to communicate with a new radio base station and a LTE base station. The circuitry is further configured to indicate a co-existence indication to the new radio base station or to the LTE base station; and receive a power control instruction for controlling power output of the transmitter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/646,574, filed Mar. 12, 2020, which is based on PCT filingPCT/EP2018/076085, filed Sep. 26, 2018, which claims priority to EP17193901.0, filed Sep. 28, 2017, the entire contents of each areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally pertains to base stations and userequipments for a mobile telecommunications system.

TECHNICAL BACKGROUND

Several generations of mobile telecommunications systems are known, e.g.the third generation (“3G”), which is based on the International MobileTelecommunications-2000 (IMT-2000) specifications, the fourth generation(“4G”), which provides capabilities as defined in the InternationalMobile Telecommunications-Advanced Standard (IMT-Advanced Standard), andthe current fifth generation (“5G”), which is under development andwhich might be put into practice in the year 2020.

A candidate for providing the requirements of 5G is the so-called LongTerm Evolution (“LTE”), which is a wireless communications technologyallowing high-speed data communications for mobile phones and dataterminals and which is already used for 4G mobile telecommunicationssystems. Other candidates for meeting the 5G requirements are termed NewRadio (NR) Access Technology Systems (NR). An NR can be based on LTEtechnology, just as LTE was based on previous generations of mobilecommunications technology.

LTE is based on the GSM/EDGE (“Global System for MobileCommunications”/“Enhanced Data rates for GSM Evolution” also calledEGPRS) of the second generation (“2G”) and UMTS/HSPA (“Universal MobileTelecommunications System”/“High Speed Packet Access”) of the thirdgeneration (“3G”) network technologies.

LTE is standardized under the control of 3GPP (“3rd GenerationPartnership Project”) and there exists a successor LTE-A (LTE Advanced)allowing higher data rates than the basic LTE and which is alsostandardized under the control of 3GPP.

For the future, 3GPP plans to further develop LTE-A such that it will beable to fulfill the technical requirements of 5G.

As the 5G system will be based on LTE or LTE-A, respectively, it isassumed that specific requirements of the 5G technologies will,basically, be dealt with by features and methods which are alreadydefined in the LTE and LTE-A standard documentation.

As discussed, in 3GPP a work Item (WI) on New Radio Access Technology(NR) has been agreed. The new Radio Access Technology (RAT) is expectedto operate in a large range of frequencies, from hundreds of MHz to 100GHz and it is expected to cover a broad range of use cases. Use cases,which are considered, are, for example:

-   -   Enhanced Mobile Broadband (eMBB)    -   Massive Machine Type Communications (mMTC)    -   Ultra Reliable & Low Latency Communications (URLLC)

At least for initial deployment, NR and LTE are expected to coexist.

Although there exist signaling techniques for LTE, it is generallydesirable to improve coexisting situations between NR and LTE.

SUMMARY

According to a first aspect, the disclosure provides a user equipmentfor a mobile telecommunications system comprising circuitry including areceiver and a transmitter and being configured to communicate with anew radio base station and a LTE base station, wherein the circuitry isfurther configured to indicate a coexistence indication to the new radiobase station or to the LTE base station; and receive a power controlinstruction for controlling power output of the transmitter.

According to a second aspect, the disclosure provides a base station fora mobile telecommunications system comprising circuitry configured tocommunicate with at least one user equipment, the at least one userequipment being configured to communicate with a new radio base stationand a LTE base station, wherein the circuitry is further configured todetect a coexistence indication; and transmit a power controlinstruction to the at least one user equipment, based on the detectedcoexistence indication.

Further aspects are set forth in the dependent claims, the followingdescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are explained by way of example with respect to theaccompanying drawings, in which:

FIG. 1 illustrates a radio access network including LTE and NR basestations;

FIG. 2 illustrates the coexistence of NR and LTE subframe transmission;

FIG. 3 illustrates the coexistence of NR and LTE transmission in thefrequency domain;

FIG. 4 illustrates a single uplink transmission scheme;

FIG. 5 illustrates a first embodiment of a mobile telecommunicationsmethod using a first trigger;

FIG. 6 illustrates a second embodiment of a mobile telecommunicationsmethod using a second trigger;

FIG. 7 illustrates a third embodiment of a mobile telecommunicationsmethod using a third trigger;

FIG. 8 illustrates a table depicting bits in a power headroom message;

FIG. 9 illustrates an embodiment of a mobile telecommunications methodusing a first event;

FIG. 10 illustrates an embodiment of a mobile telecommunications methodusing a second event;

FIG. 11 illustrates an embodiment of a mobile telecommunications methodusing a third event; and

FIG. 12 illustrates a general purpose computer which can implementanyone of the circuitries, base stations and user equipments asdescribed herein.

DETAILED DESCRIPTION OF EMBODIMENTS

Before a detailed description of the embodiments under reference of FIG.1 is given, general explanations are made.

As mentioned in the outset, several generations of mobiletelecommunications systems are known, e.g. the third generation (“3G”),the fourth generation (“4G”), which provides capabilities as defined inthe International Mobile Telecommunications-Advanced Standard(IMT-Advanced Standard), and the current fifth generation (“5G”), whichis under development and which might be put into practice in the year2020.

As discussed, a candidate for providing the requirements of 5G is theso-called Long Term Evolution (“LTE”), which is a wirelesscommunications technology allowing high-speed data communications formobile phones and data terminals and which is already used for 4G mobiletelecommunications systems. Other candidates for meeting the 5Grequirements are termed New Radio (NR) Access Technology Systems (NR).An NR can be based on LTE technology, just as LTE was based on previousgenerations of mobile communications technology.

As mentioned, LTE is based on the GSM/EDGE (“Global System for MobileCommunications”/“Enhanced Data rates for GSM Evolution” also calledEGPRS) of the second generation (“2G”) and UMTS/HSPA (“Universal MobileTelecommunications System”/“High Speed Packet Access”) of the thirdgeneration (“3G”) network technologies, and there exists the successorLTE-A (LTE Advanced) allowing higher data rates than the basic LTE andwhich is also standardized under the control of 3GPP.

As the 5G system will be based on LTE or LTE-A, respectively, it isassumed that specific requirements of the 5G technologies and, thus, ofembodiments described herein, will, basically, be dealt with by featuresand methods which are already defined in the LTE and LTE-A standarddocumentation.

As discussed, in 3GPP a work Item (WI) on New Radio Access Technology(NR) has been agreed and the new Radio Access Technology (RAT) isexpected to operate in a large range of frequencies, from hundreds ofMHz to 100 GHz and it is expected to cover a broad range of use cases,examples of which are given in the outset.

At least for initial deployment, NR and LTE are expected to coexist, asis also illustrated in FIG. 1 . FIG. 1 illustrates an embodiment of aRadio Access Network RAN 1, which has two macro cells 2 a and 2 b, whichare each established by a LTE (base station) eNodeB 3 a and 3 b.Moreover, in each of the macro cells 2 a and 2 b, a NR cell 4 a and 4 bis located, which is each established by a NR (base station) eNodeB 5 aand 5 b, respectively (the NR eNodeB may also be referred to as NR gNBor NR gNodeB).

A (user equipment) UE 6 can communicate with the LTE eNodeB 3 a and, aslong it is within the NR cell 4 a, it can also communicate with the NReNodeB 5 b.

As also illustrated in FIG. 1 , also the LTE eNodeBs 3 a and 3 b cancommunicate which each other, which is typically performed over theknown X2-interface, but, also a communication between the LTE eNodeBs 3a and 3 b and the NR eNodeBs 5 a and 5 b may be possible, e.g. over anXn-interface, which is also discussed for NR. Also the NR eNodeBs 5 aand 5 b may communicate with each other.

The coexistence may be implemented in some embodiments, by using thesame frequency resources for NR and LTE, but NR and LTE aredifferentiated using TDM (Time Division Multiplexing), e.g. NR uses LTEMBSFN (Multicast-Broadcast Single Frequency) subframes, as illustratedin FIG. 2 .

FIG. 2 illustrates an example, where there are up to a maximum of sixLTE MBSFN subframes in a radio frame. Here, exemplary, six LTE MBSFNsubframes, i.e. subframes 1, 2, 3, 6, 7, 8, are used for NRtransmissions and the remaining subframes are used for LTEtransmissions.

Another implementation, which may be used in some embodiments asillustrated in FIG. 3 , is to use separate frequency resources andimplement NR as a secondary carrier in a multi-carrier operation, i.e.LTE uses one frequency carrier (lower box in FIG. 3 ) and NR usesanother frequency carrier (upper box in FIG. 3 ).

One of the common deployment will be, in some embodiments, where LTEwill use FDD (Frequency Division Duplexing) mode of operation and NRdeploys TDD (Time Division Duplexing) mode of operation.

Such coexistence in certain frequency bands may result in twosimultaneous peaks, in some embodiments, generated by the UE on uplinkif simultaneous uplink in LTE and NR is configured and used.

Such peaks may generate intermodulation products, which will interferethe receiver in the UE and, in a case where, where for example, LTEdeploys FDD and NR deploys TDD, the LTE downlink (DL) performance mightbe impacted.

Hence, in some embodiments, for such very specific frequency allocationswithin LTE-NR band combinations, a reference sensitivity power leveldegradation may be experienced due to intermodulation distortion issues,when the dual uplink (UL) transmission is used.

Moreover, according to 3GPP document RP-172085 (“Signalling forSingle/Dual UL Tx (current status)”), a UE capability indicates that theUE is not allowed to have two simultaneous UL transmissions for RAN4specified channel allocations in a given band combination. Then,according to this document, only one uplink transmission will beactivated accordingly. RAN1#89 (May) agreed that 5G NR needs to supportnon-standalone (NSA) NR UEs, which may not be capable of transmitting ontwo uplinks at the same time when it is in a LTE-NR Dual Connectivity(DC) configuration, i.e. there is a need to support for singletransmission (Tx) UEs for LTE-NR DC. The RAN1#89 minutes states (andagreed on) the following: “For NR NSA for a UE, NR supports the casethat when the UE is configured with multiple UL carriers on differentfrequencies (where there is at least one LTE carrier and at least one NRcarrier of a different carrier frequency), the UE operates on only oneof the carriers at a given time among a pair of LTE and NR carriers . .. ”

RAN1 AH#2 (June) sent a liaison statement (LS) to RAN2, RAN3 and RAN4outlining a solution for single UL transmission for the UE operating inLTE+NR Dual connectivity mode in the LS R2-1707619 (3GPP TSG RAN WG2#99,Berlin, Germany, 21-25 Aug., 2017), summarizing, with the indicationsthat single UL transmission is supported where NW synchronizationbetween eNodeB and gNodeB is assumed (where there is at least one LTEcarrier and at least one NR carrier of a different carrier frequency)and further conditions are met, which can be taken from that document.

Furthermore, as also illustrated in FIG. 4 , according to 3GPP documentR2-1707822 (3GPP TSGRAN WG2 #99, Berlin, Germany, 21-25 Aug. 2017) anuplink activity pattern should be supported for single transmitting (Tx)UEs, and that this would be negotiated between the NR eNodeB and the(LTE) eNB.

Hence, according to currently known agreements, only the single ULtransmission will be supported on certain problematic band combinationsand the UE switches between the LTE and NR band for UL transmission, asexemplary illustrated in FIG. 4 .

Hence, it has been recognized that with a careful UL power controldesign, the simultaneous UL transmissions on LTE and NR could besupported even in such problematic band combinations, where, forexample, a “double peak” situation occurs.

Moreover, from the prior art, e.g. US 2015/0141068 A1, it is known, inthe case of an intermodulation problem due to multiple uplink componentcarriers, to set an uplink output power control value for each of thecomponent carriers and to provide a corresponding power instructing to aterminal device. However, in this prior art it assumed to reuse theconventional LTE measurement report signalling to indicate the downlinkquality to an eNodeB.

But, it has been recognized that the LTE measurement report isoriginally provided for the mobility (handover), and the suitabletrigger conditions (trigger timing, signal strength/interference level)could be different between the handover trigger and the intermodulationproblem indication. For example, if the UE reports the signal qualitydegradation (e.g. RSRQ) to NR gNodeB (or LTE eNodeB), it is importantfor the NR gNodeB (or LTE eNodeB) to distinguish the intermodulationproblem from a cellular coverage problem, since depending on the rootcause the NR gNodeB (or LTE eNodeB) should perform a different action.

In addition, as can be taken from the discussion above referring toRP-172085, the 3GPP is currently considering the restriction of morethan one Tx carrier, i.e. restriction to single UL transmission, inorder to avoid the intermodulation problem.

However, it has been recognized that if the NR gNodeB (or LTE eNodeB)receives further information from the UE, such as UE Tx power headroominformation or an implicit indication by ignoring the uplink grant, theNR gNodeB (or LTE eNodeB) could select the better option among multipleoptions (UE capability of single UL transmission, time divisionmultiplex operation for NR/LTE, power control with two UL transmissionsand so on) rather than simply confine to single UL transmissioncapability.

Therefore, some of the embodiments, pertain to a new signalling orequivalent method, as will be discussed further below.

Thereby, in some embodiments, it is possible to maximize the radioresource utilization and to make good use of high speed NR link, tosupport simultaneous LTE-NR UL transmission, even on problematic bandcombinations having intermodulation distortion issues, via powercontrol.

The corresponding trigger and signalling options and embodiments toinitiate such power control are discussed further below. In someembodiments, with different signalling options, the network can alsomake decision to switch between single and simultaneous UL transmissionswith power control of the user equipment.

Generally, power control of a user equipment using multiple carrierssimultaneously is known (see exemplary US 2015/0141068 A1) and, thus, amore detailed description of the power control itself is omitted.

Some embodiments pertain to a user equipment (UE) for a mobiletelecommunications system including circuitry including a receiver andtransmitter and being configured to communicate with a new radio basestation and a LTE base station, wherein the circuitry is furtherconfigured to indicate a coexistence indication to the new radio basestation or to the LTE base station; and receive a power controlinstruction for controlling power output of the transmitter.

The user equipment may be generally configured to communicate with a newradio base station and a LTE base station, and it may, generally,communicate in a single transmission mode (either new radio or LTE) orin a dual transmission mode, where it communicates simultaneously over anew radio and LTE uplink (or downlink). In some embodiments, the userequipment may (dynamically) switch between single transmission mode anddual transmission mode.

Generally, the LTE base station may be based on the principles of LTE(LTE-A) and the new radio (NR) base station may be based on NR RAT, asalso discussed above. The LTE base station may be based on the knowneNodeB of LTE, as one example, and the NR base station may be based onthe discussed NR eNodeB. The user equipment may be, for example, amobile phone, smartphone, a computer, tablet, tablet personal computer,or the like, including a mobile communication interface, or any otherdevice which is able to perform a mobile telecommunication via, forexample, LTE and NR, such as a hot spot device with a mobilecommunication interface, etc. Hence, in some embodiments, the userequipment is configured to perform communication with the NR basestation and the LTE base station simultaneously, such that theabove-discussed coexistence issue may occur in some embodiments.

The coexistence indication may explicitly or implicitly includeinformation about the coexistence of new radio and LTE uplink (ordownlink) transmission.

As discussed, the power control instruction may include an instructionfor reducing the output power of the UE circuitry, for example, for theNR transmission and for the LTE transmission. For instance, an outputpower value may be determined which forms an upper limit for the sum ofthe output power of the NR transmission and the output power for the LTEtransmission. The output power of the NR transmission and of the LTEtransmission may have the same value or it may have different values,wherein the sum of the NR transmission output power and the LTEtransmission output power may stay below the given output powerthreshold value. Moreover, an intermodulation power may be detected andtaken into account for determining the NR transmission output power andthe LTE transmission output power, without limiting the presentdisclosure in that regard. As discussed, for example, the principles asdisclosed in US 2015/0141068 A1 may be applied in some embodiments.

In some embodiments, the coexistence indication is indicated explicitly,e.g. by transmitting the coexistence indication to the new radio basestation and/or the LTE base station, or implicitly (e.g. withoutexplicit signaling), as will also discussed further below.

The coexistence indication may be indicated when a predefinedcombination of a new radio transmission band and a LTE transmission bandis detected. As discussed above, in some embodiments combinations of newradio transmission band and LTE transmission band are known (and mayalso be changed dynamically) and it can be known in advance that certaincombinations may result in the “double peak” situation, for example.Hence, in some embodiments, upon detection that such the UE circuitrytunes to such a known (problematic) combination, the coexistenceindication may be indicated (e.g. transmitted).

The coexistence indication may be indicated when additionally a downlinkperformance degradation is detected. Hence, in some embodiments, inaddition to the problematic band combination, also a downlinkperformance degradation must be detected and only then the coexistenceindication is indicated (e.g. transmitted).

The coexistence indication may be indicated when it is detected that thereceiver or transmitter of the UE circuitry tunes to the predefinedcombination of the new radio transmission band and the LTE transmissionband.

The coexistence indication may be indicated, based on performanceinformation associated with the combination of the new radiotransmission band and the LTE transmission band. The performanceinformation may be information collected in the past and may, thus,reflect a performance history for a specific band combination. Hence, iffrom this performance history it is known that a specific bandcombination is problematic (based on a performance below a predefinedthreshold), the coexistence indication may be indicated (e.g.transmitted).

The coexistence indication may be indicated, based on a predeterminedthreshold of an operation parameter of the receiver. The operationparameter may be indicative of a temperature of the receiver, aperformance of the receiver, power consumption of the receiver, receiversensitivity degradation or the like (based on that information it can bedetermined that the receiver might be interfered).

The coexistence indication may be indicated, based on detection of apredefined MIMO (multiple in multiple out) layer configuration. Forinstance, for predefined MIMO layer configuration it is known that thecoexistence issue may occur.

In some embodiments, the coexistence indication is indicated(transmitted) included in a power headroom message. The power headroommessage may include a data filed (one or more bits) indicating thecoexistence of NR and LTE transmission.

The power headroom message may only contain power headroom informationof serving cells associated with a predefined combination of a new radiotransmission band and a LTE transmission band. As discussed above, sucha predefined combination may be problematic (e.g. “double peak”situation may occur) and, thus, only the power headroom information ofserving cells which are associated with such a problematic bandcombination is transmitted in the power headroom message.

In some embodiments, the coexistence indication is indicated (e.g.transmitted) included in a user equipment capability signaling.

In some embodiments, as mentioned, the coexistence indication isexplicitly indicated by transmitting it to the new radio base station orto the LTE base station.

In some embodiments, the coexistence indication is implicitly indicatedby skipping an allocated uplink grant. Hence, the base station candetect that there is a coexistence indication since the user equipmentdoes not transmit any data on the granted and allocated uplink channel.

The allocated uplink grant may be on a predefined band included in apredefined (problematic, as discussed above) combination of a new radiotransmission band and a LTE transmission band.

In some embodiments, the uplink grant may refer to the uplink grant thatis allocated for uplink Semi-Persistent Scheduling.

Alternatively, if the uplink grant is high priority or high QoS required(e.g delay-sensitive QoS for URLCC applications), the UE may send bothLTE/NR uplink instead of skipping an allocated uplink grant and the UEcould ignore the downlink negative effect. For example, in the case thatthe impacted downlink subframe is not PSS/SSS/PBCH and/or PDSCH forsystem information, the UE can ignore it. The UE may need theretransmission of downlink data again, but the impact may not be (very)critical.

The coexistence indication may be indicated, based on transmission of ameasurement report, wherein the measurement report may be a channelstate information measurement report or a downlink coverage measurementreport.

The measurement report may be transmitted, based on a predefined event,wherein the predefined event may include at least one of the followinginformation: two uplinks without power restriction for intermodulationare allowed; two uplinks with power control for intermodulation areallowed; and only single uplink is allowed.

In some embodiments, the coexistence indication includes an indicationof at least one subframe for simultaneous new radio and LTE uplinktransmission. The subframe may be a TDM subframe for NR uplinktransmission and the coexistence indication may include a TDM patternconfiguration for simultaneous new radio and LTE uplink transmission.The at least one subframe may be a subframe where the DL receiver of theUE is not (or only negligible) interfered. Hence, the pattern mayindicate NR subframes where the UE can (or cannot) transmit when suchpattern is informed to the LTE base station and vice versa. The TDMpattern indicated by the coexistence indication may include the optionof single transmission or simultaneous transmissions from the UE pointof view.

Some embodiments, pertain to a base station for a mobiletelecommunications system including circuitry configured to communicatewith at least one user equipment (e.g. as discussed herein), the atleast one user equipment being configured to communicate with a newradio base station and a LTE base station, wherein the circuitry isfurther configured to detect a coexistence indication (as indicated(explicitly or implicitly by the UE, as discussed); and transmit a powercontrol instruction to the at least one user equipment, based on thedetected coexistence indication.

The base station may be a NR base station or a LTE base station asdiscussed herein.

The circuitry may detect the coexistence indication in a received powerheadroom message, as also discussed above. As discussed above, the powerheadroom message may only contain power headroom information of servingcells associated with a predefined combination of a new radiotransmission band and a LTE transmission band.

The circuitry may detect the coexistence indication in a received userequipment capability signaling.

As discussed, the coexistence indication may be received from the atleast one user equipment.

The circuitry may detect the coexistence indication by detecting thatthe at least one user equipment skipped an allocated uplink grant, asalso discussed above. This may be detected by a zero or non-existingtransmission on the granted uplink channel. As discussed, the allocateduplink grant may be on a predefined band included in a predefined(problematic, as discussed) combination of a new radio transmission bandand a LTE transmission band.

As discussed, the coexistence indication may be detected, based on ameasurement report received from the at least one user equipment,wherein the measurement report may be a channel state informationmeasurement report or a downlink coverage measurement report.

In some embodiments, as discussed above, the measurement report isreceived, based on a predefined event (wherein the predefined event isdetected by the UE as discussed above).

The predefined event may include two uplinks without power restrictionfor intermodulation are allowed, which may be the case for example, whenthe UE is near a center of a macro cell or the like. This informationmay include a signal strength measurement information or a channelquality indicator information. Hence, based on the signal strength orchannel quality indicator, the circuitry may determine whether the UEcan use the dual (uplink) transmission mode or only a single (uplink)transmission mode. The power control instruction includes information toactivate an LTE uplink and a new radio uplink when the signal strengthor the quality indicator is above a predefined threshold.

In some embodiments, the predefined event includes “two uplinks withpower control for intermodulation are allowed” information, and thus,the power control instruction may include power control information tocontrol output power of the transmitter of the at least one userequipment.

In some embodiments, the predefined event includes only single uplink isallowed information, and, thus, the power control instruction mayinclude information to activate only one uplink channel. Hence, the userequipment performs single (uplink) transmission either in the NR or LTEband.

In some embodiments, the coexistence indication includes an indicationof at least one subframe for simultaneous new radio and LTE uplinktransmission, as also discussed above. Hence, the base station may useaccording subframes for transmission, which (likely) do not lead to the“double peak” situation and, thus, may not interfere the downlinkreceiver of the UE.

Hence, in some embodiments, it is only the UE which has the ability todetect the co-existence problem due to intermodulation issue and thenetwork has no direct understanding of whether a UE is experiencingperformance degradation due to LTE-NR co-existence or not. Thus, some ofthe embodiments, as discussed, provide a UE that sends a coexistenceindication to the network once the problem occurs, such that the networkgets knowledge about the coexistence problem.

Although above processes have been described for a (NR/LTE) base stationand a user equipment, the processes described herein may also pertain toa method for mobile telecommunications.

The methods as described herein are also implemented in some embodimentsas a computer program causing a computer and/or a processor and/orcircuitry to perform the method, when being carried out on the computerand/or processor and/or circuitry. In some embodiments, also anontransitory computer-readable recording medium is provided that storestherein a computer program product, which, when executed by aprocessor/circuitry, such as the processor/circuitry described herein,causes the methods described herein to be performed.

Triggers for UE to Send Coexistence Indication to Network

Returning to FIG. 5 , there is illustrated a first embodiment of amobile telecommunications system method 20, which may be performed bythe UE (e.g. UE 6 of FIG. 1 ) and an associated eNodeB (NR eNodeB 5 a (5b) or LTE eNodeB 3 a (3 b)) and which uses a first type of trigger(performance degradation).

At 21, the UE detects a downlink (LTE or NR) performance degradation,e.g. based on the fact that it can't decode LTE PDCCH or the RSRP on thereference signal is below certain threshold.

At 22, the UE additionally correlates this sudden decrease in radioconditions with simultaneous uplink transmission timing on problematicband combinations.

When the trigger condition at 21 occurs, the UE transmits at 23 thecoexistence indication to the eNodeB (NR and/or LTE), which receivesthis coexistence indication at 24.

The eNodeB analyzes the coexistence indication and transmits acorresponding power control instruction at 25 to the UE, which isreceived by the UE at 26. At 27, the UE (its circuitry) controls powerof the transmitter circuitry in accordance with the received powercontrol instruction.

FIG. 6 illustrates a second embodiment of a mobile telecommunicationssystem method 30, which may be performed by the UE (e.g. UE 6 of FIG. 1) and an associated eNodeB (NR eNodeB 5 a (5 b) or LTE eNodeB 3 a (3 b))and which uses second type of trigger (tuning to problematic channel).

At 31, the UE detects that the circuitry (receiver/transmitter) is goingto tune onto a problematic band, which may be a NR band or LTE band of aproblematic combination, as discussed above, where, for example, adouble peak situation may occur.

Before the UE experiences a potential downlink performance degradation,the UE sends, at 32, a coexistence indication to the network for furtherUL transmit power instructions. The UE may also know the problematicband from previous experience, which may be stored information in astorage.

The network, e.g. eNodeB (NR and/or LTE) receives the coexistenceindication at 33 and transmits, based on the received coexistenceindication, a power control instruction to the UE at 34, which isreceived by the UE at 35. At 36, the UE performs power control inaccordance with the received power control instruction.

FIG. 7 illustrates a third embodiment of a mobile telecommunicationssystem method 40, which may be performed by the UE (e.g. UE 6 of FIG. 1) and an associated eNodeB (NR eNodeB 5 a (5 b) or LTE eNodeB 3 a (3 b))and which uses a third type of trigger (overheating and degradation ofreceiver sensitivity).

At 41, the UE detects a problematic band combinations based on detectingoverheating and/or degradation of the receiver sensitivity, i.e. basedon an operation parameter of the receiver. The problematic bandcombination may also be detected, based on an enhanced MIMO layerconfiguration.

The UE sends, at 42, a coexistence indication to the network for furtherUL transmit power instructions.

The network, e.g. eNodeB (NR and/or LTE) receives the coexistenceindication at 43 and transmits, based on the received coexistenceindication, a power control instruction to the UE at 44, which isreceived by the UE at 45. At 46, the UE performs power control inaccordance with the received power control instruction.

Coexistence Indication and its Variations

Option 1: One Shot PHR

In LTE, the power headroom reporting (PHR) is used to provide theserving cell with the information about the difference between thenominal UE maximum transmit power and the estimated power for UL-SCHtransmission per activated serving cell. PHR will be triggered bypathloss change or timer.

In an embodiment, a trigger is used which will be based on whencoexistence issue has been observed by the UE.

In this embodiment, the coexistence indication will be sent by the UE ina one shot PHR, e.g. on NR uplink or on LTE uplink (in the case that LTEis going to include this) according to at least one of the triggers asdefined above (see embodiments of FIGS. 5 to 7 ).

The format of this PHR can refer to the LTE spec 36.321 (3GPP TS 36.321V14.4.0 (2017-09), 3rd Generation Partnership Project; TechnicalSpecification Group Radio Access Network; Evolved Universal TerrestrialRadio Access (E-UTRA); Medium Access Control (MAC) protocolspecification, (Release 14)), see table 6.1.3.6b-1: Dual ConnectivityPHR MAC Control Element, which is illustrated in FIG. 8 .

One bit of the bits in this table of FIG. 8 can be used to indicateLTE-NR coexistence.

Moreover, the PHR can only contain the PH information on the servingcells (e.g. cell 2 a/b or 4 a/b of FIG. 1 ) of problematic bandcombinations and the network can optionally take the previously receivedPHR by the same UE which is triggered by periodic timer into account forthe power adjustment.

After receiving the one shot PHR from the UE (including the coexistenceindication), the network, e.g. eNodeB (NR and/or LTE) can identify theproblem and send the power control command on LTE and NR downlink inorder to adjust the uplink LTE and NR UL transmit power to address theintermodulation problem, as also discussed above for the embodiments ofFIGS. 5 to 7 .

Option 2: UE Capability Signaling

In another embodiment, the UE sends the problematic band combination(coexistence indication) on which the UE is experiencing performancedegradation or potentially going to be impacted by the simultaneous ULtransmissions in the (temporary) UE capability signaling.

In another embodiment, in the UE capability signaling, the UE can deletethe problematic band combinations (predefined by RAN4 as example) onwhich simultaneous uplink transmission could be supported with properpower control. With this, network can potentially support thesimultaneous uplink transmissions on certain problematic bandcombinations. Or a new RRC signaling to support this can be defined.

As also discussed above for embodiments of FIGS. 5 to 7 , afterreceiving this information (i.e. coexistence indication), the network(e.g. eNodeB (NR and/or LTE) will adjust the LTE and NR UL transmitpower accordingly by transmitting a power control instruction to the UE.

Since UE capability is exchanged at the time of attach or downloadedfrom the MME (Mobile Management Entity), the traditional UE capabilityframework does not offer flexibility to dynamically signal the powercontrol situation, such that in this embodiment, the temporarycapability information exchange procedure is used. Temporary UEcapability procedure is standardized for the cases where e.g.overheating takes place in the UE and these principles are implementedaccordingly in this embodiment.

Option 3: Skip UL Grant as an Implicit Indication

In another embodiment, the UE skips the allocated UL grant on theproblematic band as an implicit indication of the coexistence indicationto the network (e.g. eNodeB (NR and/or LTE) and does not transmit userdata.

As discussed above for embodiments of FIGS. 5 to 7 , in response toreceipt of the coexistence indication, the network (e.g. eNodeB (NRand/or LTE) will adjust the corresponding transmit power in LTE and NRUL after detecting a null transmission on the allocated UL grant(channel).

Normally, the network will request the UE to increase power allocationif it detects missed transmission for a grant assuming that the UE radioconditions have deteriorated. However, this option requires that the UEreduces its power. Therefore, this option is used with other options inorder for the network to identify that an intermodulation issue occurs.

Option 4: New Events of Measurement Report

In these embodiments, the conventional measurement report mechanismbased on downlink coverage or CSI measurements reporting is reused, butnew events/reporting criteria are introduced, since the conventional LTEhas RRM (Radio Resource Management) events A,B,C are mainly for mobilityfunctions such as intra/inter frequency handover, carrier aggregationScell addition/remove.

In the following, three different embodiments using additional eventsfor IM (intermodulation) to set the optimal thresholds/triggerconditions are described. And the parameters in these events e.g.thresholds could be configured/updated by network.

Event IM1 (“Two Uplinks without Power Restriction for Intermodulationare Allowed”)

FIG. 9 illustrates an embodiment of a mobile telecommunications systemmethod 50, which may be performed by the UE (e.g. UE 6 of FIG. 1 ) andan associated eNodeB (NR eNodeB 5 a (5 b) or LTE eNodeB 3 a (3 b)).

In this embodiment, this event means that that UE has no restriction ofUL and, thus, can transmit in the dual mode (i.e. NR and LTEsimultaneously), wherein at 51, the UE detects this event (i.e. that thedual mode is possible without restriction).

In this event IM1 “two uplinks without power restriction forintermodulation are allowed”, for example, the signal strength (RSRP) orCQI (Channel Quality Indicator) measurements is better than apre-defined value, which means that the UE is near the center of aserving (macro) cell (e.g. LTE cell 2 a/b or NR cell 4 a/b).

The UE transmits the corresponding measurement report (coexistenceindication) at 52 to the network, e.g. eNodeB (NR and/or LTE), which isreceived at 53 by the network, e.g. eNodeB (LTE or NR).

The eNodeB (NR and/or LTE) determines a corresponding power controlinstruction, at 54, based on the received measurement report and thatunder this circumstance the UE Tx power level could be low. In addition,it is determined that a signal quality (RSRQ) is better than apre-define value, which means that a small impact of Intermodulation isexpected.

In that case, the eNodeB (NR and/or LTE) activates both the LTE UL andthe NR UL without restriction by transmitting a corresponding powercontrol instruction to the UE at 55, wherein the UE receives thisinstruction at 56 and controls in accordance with the received powercontrol instruction the transmitter.

Event IM2 “Two Uplinks with Power Control for Intermodulation areAllowed”)

FIG. 10 illustrates an embodiment of a mobile telecommunications systemmethod 60, which may be performed by the UE (e.g. UE 6 of FIG. 1 ) andan associated eNodeB (NR eNodeB 5 a (5 b) or LTE eNodeB 3 a (3 b)).

This event IM2 means two uplinks are allowed with TDM or under powercontrol (or similar to option 1), and at 61 the UE detects this eventand the UE transmits at 63 a corresponding measurement report which isreceived at 63 by the network, e.g. eNodeB (NR and/or LTE).

Based on the measurement report, the eNodeB (NR and/or LTE) determinescorresponding power control instruction at 64.

At 65, the eNodeB (NR or LTE) activates the selected solution of IM, forexample, the temporary Tx power restriction, power transmitting thepower control construction at 65, which is received at 66 by the UE andthe UE controls the transmitter accordingly.

The thresholds for activating a corresponding solution of IM (powercontrol) depend on the combination of bands/frequency.

Event IM3 (“Only Single Uplink is Allowed”)

FIG. 11 illustrates an embodiment of a mobile telecommunications systemmethod 60, which may be performed by the UE (e.g. UE 6 of FIG. 1 ) andan associated eNodeB (NR eNodeB 5 a (5 b) or LTE eNodeB 3 a (3 b)).

In this embodiment, this event IM3 means only single UL is allowed,which is detected by the UE at 71 and the UE transmits a correspondingmeasurement report at 72, which is received by the network, e.g. eNodeB(NR and/or LTE) at 73.

In this event, for example, a signal strength is better than apre-defined value, but the signal quality is worse than a pre-definedvalue.

Hence, the power control solution could be useless under highinterference circumstance.

Alternatively, for example, a signal strength is worse than apre-defined value, which means the UE may be required to transmit athigh power.

Based on this, the eNodeB (NR and/or LTE) determines a power controlinstruction at 74 and transmits it, at 75, wherein the UE receives thepower control instruction, at 76, and performs control of thetransmitter accordingly.

In some embodiments, it is common to the above events if they areconfigured as RRM measurement events that these events have anoffset/hysteresis (in the time domain).

In particular, in the embodiments of event IM2 and event IM3 themeasurement report should be transmitted (a little bit) earlier thanaccording to the timing when the IM problem becomes severe, since,otherwise, the UE could miss the opportunity to transmit the event(measurement report).

Summarizing, in some embodiments, in order to maximize the radioresource utilization and for making full use of high speed NR link, someembodiments support simultaneous LTE-NR UL transmission even onproblematic band combinations via power control.

In contrast to current discussions in prior art, where only the singleTX is supported for LTE-NR coexistence on certain band combinations,some embodiments allow the simultaneous LTE-NR UL transmission even inproblematic band combinations with careful power control strategy, asdiscussed above, also based on providing corresponding trigger andsignalling options to initiate such power control.

In the following, an embodiment of a general purpose computer 130 isdescribed under reference of FIG. 12 . The computer 130 can beimplemented such that it can basically function as any type of basestation or new radio base station, transmission and reception point, oruser equipment as described herein. The computer has components 131 to140, which can form a circuitry, such as any one of the circuitries ofthe base stations, and user equipments, as described herein.

Embodiments which use software, firmware, programs or the like forperforming the methods as described herein can be installed on computer130, which is then configured to be suitable for the concreteembodiment.

The computer 130 has a CPU 131 (Central Processing Unit), which canexecute various types of procedures and methods as described herein, forexample, in accordance with programs stored in a read-only memory (ROM)132, stored in a storage 137 and loaded into a random access memory(RAM) 133, stored on a medium 140 which can be inserted in a respectivedrive 139, etc.

The CPU 131, the ROM 132 and the RAM 133 are connected with a bus 141,which in turn is connected to an input/output interface 134. The numberof CPUs, memories and storages is only exemplary, and the skilled personwill appreciate that the computer 130 can be adapted and configuredaccordingly for meeting specific requirements which arise, when itfunctions as a base station, and user equipment.

At the input/output interface 134 several components are connected: aninput 135, an output 136, the storage 137, a communication interface 138and the drive 139, into which a medium 140 (compact disc, digital videodisc, compact flash memory, or the like) can be inserted.

The input 135 can be a pointer device (mouse, graphic tablet, or thelike), a keyboard, a microphone, a camera, a touchscreen, etc.

The output 136 can have a display (liquid crystal display, cathode raytube display, light emittance diode display, etc.), loudspeakers, etc.

The storage 137 can have a hard disk, a solid state drive and the like.

The communication interface 138 can be adapted to communicate, forexample, via a local area network (LAN), wireless local area network(WLAN), mobile telecommunications system (GSM, UMTS, LTE, NR etc.),Bluetooth, infrared, etc.

It should be noted that the description above only pertains to anexample configuration of computer 130. Alternative configurations may beimplemented with additional or other sensors, storage devices,interfaces or the like. For example, the communication interface 138 maysupport other radio access technologies than the mentioned UMTS, LTE andNR.

When the computer 130 functions as a base station, the communicationinterface 138 can further have a respective air interface (providinge.g. E-UTRA protocols OFDMA (downlink) and SCFDMA (uplink)) and networkinterfaces (implementing for example protocols such as S1-AP, GTPU,S1-MME, X2-AP, or the like). Moreover, the computer 130 may have one ormore antennas and/or an antenna array. The present disclosure is notlimited to any particularities of such protocols.

It should be recognized that the embodiments describe methods with anexemplary ordering of method steps. The specific ordering of methodsteps is however given for illustrative purposes only and should not beconstrued as binding.

All units and entities described in this specification and claimed inthe appended claims can, if not stated otherwise, be implemented asintegrated circuit logic, for example on a chip, and functionalityprovided by such units and entities can, if not stated otherwise, beimplemented by software.

In so far as the embodiments of the disclosure described above areimplemented, at least in part, using software-controlled data processingapparatus, it will be appreciated that a computer program providing suchsoftware control and a transmission, storage or other medium by whichsuch a computer program is provided are envisaged as aspects of thepresent disclosure.

Note that the present technology can also be configured as describedbelow.

(1) A user equipment for a mobile telecommunications system comprisingcircuitry including a receiver and a transmitter and being configured tocommunicate with a new radio base station and a LTE base station,wherein the circuitry is further configured to:

indicate a coexistence indication to the new radio base station or tothe LTE base station; and

receive a power control instruction for controlling power output of thetransmitter.

(2) The user equipment of (1), wherein the coexistence indication isindicated when a predefined combination of a new radio transmission bandand a LTE transmission band is detected.

(3) The user equipment of (2), wherein the coexistence indication isindicated when additionally a downlink performance degradation isdetected.

(4) The user equipment of (2), wherein the coexistence indication isindicated when it is detected that the receiver or transmitter tunes tothe predefined combination of the new radio transmission band and theLTE transmission band.

(5) The user equipment of (4), wherein the coexistence indication isindicated, based on performance information associated with thecombination of the new radio transmission band and the LTE transmissionband.

(6) The user equipment of anyone of (1) to (5), wherein the coexistenceindication is indicated, based on a predetermined threshold of anoperation parameter of the receiver.

(7) The user equipment of anyone of (1) to (6), wherein the coexistenceindication is indicated, based on detection of a predefined MIMO layerconfiguration.

(8) The user equipment of anyone of (1) of (7), wherein the coexistenceindication is indicated included in a power headroom message.

(9) The user equipment of (8), wherein the power headroom message onlycontains power headroom information of serving cells associated with apredefined combination of a new radio transmission band and a LTEtransmission band.

(10) The user equipment of anyone of (1) to (9), wherein the coexistenceindication is indicated included in a user equipment capabilitysignaling.

(11) The user equipment of anyone of (1) to (10), wherein thecoexistence indication is explicitly indicated by transmitting it to thenew radio base station or to the LTE base station.

(12) The user equipment of anyone of (1) to (11), wherein thecoexistence indication is implicitly indicated by skipping an allocateduplink grant.

(13) The user equipment of (12), wherein the allocated uplink grant ison a predefined band included in a predefined combination of a new radiotransmission band and a LTE transmission band.

(14) The user equipment of anyone of (1) to (13), wherein thecoexistence indication is indicated, based on transmission of ameasurement report.

(15) The user equipment of (14), wherein the measurement report is achannel state information measurement report or a downlink coveragemeasurement report.

(16) The user equipment of (14) or (15), wherein the measurement reportis transmitted, based on a predefined event.

(17) The user equipment of (16), wherein the predefined event includesat least one of the following information: two uplinks without powerrestriction for intermodulation are allowed, two uplinks with powercontrol for intermodulation are allowed, only single uplink is allowed.(18) The user equipment of (1), wherein the coexistence indicationincludes an indication of at least one subframe for simultaneous newradio and LTE uplink transmission.(19) A base station for a mobile telecommunications system comprisingcircuitry configured to communicate with at least one user equipment,the at least one user equipment being configured to communicate with anew radio base station and a LTE base station, wherein the circuitry isfurther configured to:

detect a coexistence indication; and

transmit a power control instruction to the at least one user equipment,based on the detected coexistence indication.

(20) The base station of (19), wherein the coexistence indication isdetected in a received power headroom message.

(21) The base station of (19) or (20), wherein the power headroommessage only contains power headroom information of serving cellsassociated with a predefined combination of a new radio transmissionband and a LTE transmission band.

(22) The base station of anyone of (19) to (21), wherein the coexistenceindication is detected in a received user equipment capabilitysignaling.

(23) The base station of anyone of (19) to (22), wherein the coexistenceindication is received from the at least one user equipment.

(24) The base station of anyone of (19) to (23), wherein the coexistenceindication is detected by detecting that the at least one user equipmentskipped an allocated uplink grant.

(25) The base station of (24), wherein the allocated uplink grant is ona predefined band included in a predefined combination of a new radiotransmission band and a LTE transmission band.

(26) The base station of anyone of (19) to (25), wherein the coexistenceindication is detected, based on a measurement report received from theat least one user equipment.

(27) The base station of (26), wherein the measurement report is achannel state information measurement report or a downlink coveragemeasurement report.

(28) The base station of (26) or (27), wherein the measurement report isreceived, based on a predefined event.

(29) The base station of (28), wherein the predefined event includes twouplinks without power restriction for intermodulation are allowedinformation.

(30) The base station of (29), wherein the two uplinks without powerrestriction for intermodulation are allowed information includes asignal strength measurement information or a channel quality indicatorinformation.

(31) The base station of (30), wherein the power control instructionincludes information to activate an LTE uplink and a new radio uplinkwhen the signal strength or the quality indicator is above a predefinedthreshold.

(32) The base station of (28), wherein the predefined event includes twouplinks with power control for intermodulation are allowed information.

(33) The base station of (32), wherein the power control instructionincludes power control information to control output power of thetransmitter of the at least one user equipment.

(34) The base station of (28), wherein the predefined event includesonly single uplink is allowed information.

(35) The base station of (34), wherein the power control instructionincludes information to activate only one uplink channel.

(36) The base station of anyone of (19) to (35), wherein the coexistenceindication includes an indication of at least one subframe forsimultaneous new radio and LTE uplink transmission.

The invention claimed is:
 1. A user equipment for a mobiletelecommunications system comprising circuitry including a receiver anda transmitter and being configured to communicate with a new radio basestation and a LTE base station, wherein the circuitry is furtherconfigured to: detect that the receiver or transmitter is going to tuneto a predefined combination of a new radio transmission band and a LTEtransmission band, wherein the predefined combination is a knownintermodulation problematic band combination, before the user equipmentexperiences a performance degradation in response to tuning onto theknown problematic band combination, indicate a coexistence indication tothe new radio base station or to the LTE base station; and receive apower control instruction for controlling power output of thetransmitter based on a predefined threshold.
 2. The user equipment ofclaim 1, wherein the coexistence indication is indicated when apredefined combination of the new radio transmission band and the LTEtransmission band is detected.
 3. The user equipment of claim 2, whereinthe coexistence indication is indicated when additionally a downlinkperformance degradation is detected.
 4. The user equipment of claim 1,wherein the coexistence indication is indicated based on performanceinformation associated with the combination of the new radiotransmission band and the LTE transmission band.
 5. The user equipmentof claim 1, wherein the coexistence indication is indicated, based on apredetermined threshold of an operation parameter of the receiver. 6.The user equipment of claim 1, wherein the coexistence indication isindicated based on detection of a predefined MIMO layer configuration.7. The user equipment of claim 1, wherein the coexistence indication isindicated included in a power headroom message.
 8. The user equipment ofclaim 7, wherein the power headroom message only contains power headroominformation of serving cells associated with a predefined combination ofa new radio transmission band and a LTE transmission band.
 9. The userequipment of claim 1, wherein the coexistence indication is indicatedincluded in a user equipment capability signaling.
 10. The userequipment of claim 1, wherein the coexistence indication is explicitlyindicated by transmitting it to the new radio base station or to the LTEbase station.
 11. The user equipment of claim 1, wherein the coexistenceindication is implicitly indicated by skipping an allocated uplinkgrant.
 12. The user equipment of claim 11, wherein the allocated uplinkgrant is on a predefined band included in a predefined combination of anew radio transmission band and a LTE transmission band.
 13. The userequipment of claim 1, wherein the coexistence indication is indicated,based on transmission of a measurement report.
 14. The user equipment ofclaim 13, wherein the measurement report is a channel state informationmeasurement report or a downlink coverage measurement report.
 15. Theuser equipment of claim 13, wherein the measurement report istransmitted based on a predefined event.
 16. The user equipment of claim15, wherein the predefined event includes at least one of the followinginformation: two uplinks without power restriction for intermodulationare allowed, two uplinks with power control for intermodulation areallowed, only single uplink is allowed.
 17. The user equipment of claim1, wherein the coexistence indication includes an indication of at leastone subframe for simultaneous new radio and LTE uplink transmission. 18.A base station for a mobile telecommunications system comprisingcircuitry configured to communicate with at least one user equipment,the at least one user equipment being configured to communicate with anew radio base station and a LTE base station, wherein the circuitry isfurther configured to: detect a coexistence indication before the userequipment experiences a performance degradation in response to tuningonto a predefined combination of a new radio transmission band and a LTEtransmission band, wherein the predefined combination is a knownintermodulation problematic band combination; and transmit a powercontrol instruction to the at least one user equipment based on thedetected coexistence indication.
 19. The base station of claim 18,wherein the coexistence indication is detected in a received powerheadroom message.
 20. The base station of claim 19, wherein the powerheadroom message only contains power headroom information of servingcells associated with a predefined combination of a new radiotransmission band and a LTE transmission band.